Solar energy optimization device, solar energy generation system and power conversion system using the same

Abstract

A solar energy optimization device, a solar energy generation system and a power conversion system using the same are provided. The solar energy optimization device includes a plurality of conversion circuits and a plurality of control circuits. Each of conversion circuits is individually connected in series with a solar module. The conversion circuits and the solar modules are connected in series to a maximum power point tracking (MPPT) circuit. The MPPT circuit is configured to determine a photovoltaic current according to the solar modules. Each of the conversion circuits is used for converting a photovoltaic voltage of one of the solar modules into an output voltage. Each of the control circuits is used to adjust a conversion parameter of one of the conversion circuits to increase the output voltage thereof, so that an output power of each of the solar modules is optimized based on the photovoltaic current.

What is claimed is: 
     
         1 . A solar energy optimization device, comprising:
 a plurality of conversion circuits, wherein each of the conversion circuits is individually connected in series with a solar module, the conversion circuits and the solar modules are connected in series to a maximum power point tracking (MPPT) circuit, the MPPT circuit is configured to determine a photovoltaic current according to the solar modules, and each of the conversion circuits is used for converting a photovoltaic voltage of one of the solar modules into an output voltage; and   a plurality of control circuits, wherein each of the control circuits is used to adjust a conversion parameter of one of the conversion circuits to increase the output voltage thereof, so that an output power of each of the solar modules is optimized based on the photovoltaic current.   
     
     
         2 . The solar energy optimization device according to  claim 1 , wherein
 each of the control circuits is configured to adjust one of the conversion parameters in a first direction;   if one of the photovoltaic voltages or one of the output voltages is pulled up, the control circuit corresponding thereto continues to adjust the conversion parameter in the first direction;   if one of the photovoltaic voltages or one of the output voltages is pulled down, the control circuit corresponding thereto adjusts the conversion parameter in a second direction which is opposite to the first direction.   
     
     
         3 . The solar energy optimization device according to  claim 1 , wherein the output voltages of the solar modules which are optimized are not exactly identical. 
     
     
         4 . The solar energy optimization device according to  claim 1 , wherein one of the solar modules includes a plurality of solar boards connected in parallel. 
     
     
         5 . The solar energy optimization device according to  claim 1 , wherein one of the solar modules includes only one solar board. 
     
     
         6 . The solar energy optimization device according to  claim 1 , wherein each of the conversion parameters is a duty cycle or a frequency. 
     
     
         7 . The solar energy optimization device according to  claim 1 , wherein each of the control circuits is connected to one of the output terminals of the conversion circuits, so that the output voltages are fed back to the control circuits respectively. 
     
     
         8 . The solar energy optimization device according to  claim 1 , wherein each of the control circuits is connected to one of the output terminals of the solar modules, so that the photovoltaic voltages are fed back to the control circuits respectively. 
     
     
         9 . The solar energy optimization device according to  claim 1 , wherein each of the conversion circuits includes a first switch element and a second switch element, and each of the control circuits is connected to one of the first switch elements and one of the second switch elements, so that the conversion circuits are controlled by the control circuits respectively. 
     
     
         10 . A solar energy generation system, comprising:
 a plurality of solar modules;   a plurality of conversion circuits, wherein the conversion circuits and the solar modules are alternately connected in series;   a maximum power point tracking (MPPT) circuit, wherein the conversion circuits and the solar modules are connected in series to the MPPT circuit, the MPPT circuit is configured to determine a photovoltaic current according to the solar modules, and each of the conversion circuits is used to convert a photovoltaic voltage of one of the solar modules into an output voltage; and   a plurality of control circuits, wherein each of the control circuits is used to adjust a conversion parameter of one of the conversion circuits to increase the output voltage thereof, so that an output power of each of the solar modules is optimized based on the photovoltaic current.   
     
     
         11 . A power conversion system, comprising:
 a first conversion device, including a first input end, a conversion circuit, a first output end and a first control unit, wherein the first input end is electrically coupled to a first power source, and the conversion circuit is electrically coupled to the first input end, the first output end and the first control unit;   a second conversion device, including a second input end, a conversion circuit, a second output end and a second control unit, wherein the second input end is electrically coupled to a second power source, and the conversion circuit is electrically coupled to the second input end, the second output end and the second control unit; and   a maximum power point tracking (MPPT) circuit, connected in series with the first output end and the second output end,   wherein the first control unit is configured to output a first control signal to adjust a first output voltage of the conversion circuit, and the second control unit is configured to output a second control signal to adjust a second output voltage of the conversion circuit.   
     
     
         12 . The power conversion system according to  claim 11 , wherein the first output voltage is not equal to the second output voltage. 
     
     
         13 . The power conversion system according to  claim 11 , wherein the first control signal and the second control signal are Pulse Width Modulation (PWM) signals. 
     
     
         14 . The power conversion system according to  claim 11 , wherein the first control unit is configured to adjust the first control signal to change the first output voltage, and the second control unit is configured to adjust the second control signal to change the second output voltage. 
     
     
         15 . The power conversion system according to  claim 14 , wherein the first control unit is configured to adjust a duty cycle or a frequency of the first control signal, and the second control unit is configured to adjust a duty cycle or a frequency of the second control signal. 
     
     
         16 . The power conversion system according to  claim 15 , wherein if the first output voltage is increased in response to an increasing of the duty cycle or the frequency of the first control signal, the first control unit continues to increase the duty cycle or the frequency of the first control signal; if the first output voltage is decreased in response to the increasing of the duty cycle or the frequency of the first control signal, the first control unit decreases the duty cycle or the frequency of the first control signal. 
     
     
         17 . The power conversion system according to  claim 15 , wherein if the second output voltage is increased in response to an increasing of the duty cycle or the frequency of the second control signal, the second control unit continues to increase the duty cycle or the frequency of the second control signal; if the second output voltage is decreased in response to the increasing of the duty cycle or the frequency of the second control signal, the second control unit decreases the duty cycle or the frequency of the second control signal.